Client: Post Oak Savannah Groundwater Conservation District (POSGCD)
Location: Milam and Burleson Counties, Texas
Challenge. Provide technical, planning, and permitting support required to help conserve and protect groundwater resources
Solution. INTERA has provided POSGCD with a wide range of services to help manage ground water resources in Milam and Burleson counties. To update the District’s Management Plan, we defined groundwater management zones, water supply demands and sources, historical groundwater pumping, groundwater water budgets, groundwater availability, and management goals and metrics for six aquifers in the District. Working with POSGCD staff and legal counsel, INTERA helped to draft and finalize District rules for well spacing, correlative rights, well permitting, water level monitoring, aquifer production, well registration, and reporting. In addition, we developed rules regarding pumping and well permitting based on consideration of aquifer vulnerability, drought conditions, correlative rights, well depth, historical use, measured historical water declines, and simulated future water level declines. To help address the local water needs of the oil and gas industry, INTERA developed well spacing rules that allow higher production rates if groundwater wells are drilled deeper than other existing nearby wells. In support of the joint regional planning process, we helped POSGCD and its neighboring groundwater conservation districts (GCDs) to establish, monitor, and achieve desired future conditions (DFCs)—measureable properties of aquifers such as water levels and spring flow that can represent desired conditions to be achieved through prudent management practices. Working with stakeholders, INTERA has evaluated alternative DFCs with respect to the legislative requirement of balancing the highest practical pumping against the conservation of groundwater resources based on private property rights, social and economic impacts, land subsidence impacts, supply needs and management strategies, hydrological conditions, aquifer uses or conditions, and environmental impacts. On behalf of POSGCD, we review well operating permit applications for aquifer assignment, proper well construction, adequate well spacing to nearby wells, appropriate spacing and variances to property boundaries, and sufficient acreage for the proposed pumping rates. For large multi-well permits that exceed 5,000 AFY, INTERA conducts hydrogeological assessments to evaluate both local and regional impacts of the proposed pumping. To investigate regional impacts, INTERA uses GAMs to determine the effect that the proposed permitted pumping will have on average water level declines across a management zone and at specific wells of concerns, and the on water quality changes in the vicinity of the permitted wells. During the legislative session in Texas, INTERA reviews and comments on draft bills and related documents that can impact the legislative mandated management of groundwater resources by GCDs such as aquifer storage and recovery, the development of brackish groundwater zones, long-term permitting, joint regional planning, export fees, and regional water planning. Additional work for the District includes performing multiple geohydrologic studies to characterize the properties and groundwater flow in the Brazos River Alluvium, Queen City, Sparta, Yegua-Jackson, Northern Trinity, and Carrizo-Wilcox aquifers, designing a monitoring well network, and developing an Access database to assist in managing information from some 8,000 registered wells and 700 permitted wells.